Fiter design is the process of designing a filter.

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Hilbert FIR Filter for Q - Matching Filter for I

For an ultrasound application, I am collecting data from an ADC using high spec Altera FPGA which grabs data and can then do some DSP processing that would be otherwise too slow for a desktop to do. ...
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11 views

frequency response of Cosine modulated filter bank is odd (matlab example) [closed]

Take the following matlab code and run ...
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25 views

How are these pole zero plots created

Back around 5 BC, where C stands for the programming language, engineers would photograph their oscilloscope's display to record their test results. This appears to be such a photograph, taken from ...
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25 views

Stopband Attenuation

Why is a stopband attenuation of -40dB preferred for the filter design & analysis. I understand at this magnitude response point, the o/p is just 0.01 of the O/P but how does it help in defining ...
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30 views

Can we determine if a filter is butterworth or chebyshev from its physical topology?

Can all analog filters be classified as Bessel, Elliptic, Butterworth or Chebyshev? Given a physical ladder topology of several stages of {L, C or LC} in {series or parallel}, is it possible to ...
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53 views

How can a signal have two maximum frequency components?

$x(t)$ can be exactly reconstructed from its samples at $\omega_s = 10 \textrm{ rad/sec}$. My conclusion is that the maximum frequency component in $x(t)$ is $5\textrm{ rad/sec}$. But I'm being told ...
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Analytical way to generate an IIR that is the square root response of another IIR

For simplicity take the transfer function of a second order IIR in $z$-domain: $$ H(z) = \frac {b_0 + b_1 z^{-1} + b_2 z^{-2}} {a_0 + a_1 z^{-1} + a_2 z^{-2}} $$ Is it possible to generate a new ...
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21 views

describing a block diagram // How do I describe multiplying a signal through multiple branches formally?

Let's say I made this block diagram and I want to explain it: FYI: $x$ is a signal and each $y$ box is a matrix I want to say that: The signal $x$ is multiplied by each matrix $y$ in the ...
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45 views

What is the difference between a'mixer' and a ' multiplier' used in modulation process?

I am not sure if it is valid to conclude that a mixer produces a difference/sum of frequencies at output ,while multiplier produces multiples of frequency at its output. I am keen to know how far I ...
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15 views

How to design Bi orthogonal wavelet filter bank

I know in orthogonal wavelet system analysis filters can be made by flipping the synthesis filters(vice versa) but in bi orthogonal system this will not work because the co efficient are symmetric in ...
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26 views

FIR anti aliasing filter design

Suppose we have a signal with a $3\mathrm{kHz}$ bandwidth and a sampling rate of $48\mathrm{kHz}$. Then we want to decimate ($6$-rate decimator) it, in which the decimator has a passband ripple of ...
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37 views

Filter Design near Nyquist frequency (complex curve fitting)

I'm fitting IIR filters to a complex transfer function with Matlab's invfreqz.m. My fitting results are very good, but when I come very close to the Nyquist frequency the phase response runs to 0 and ...
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33 views

Wavelet filter coefficients from scaling filter coefficients

I am trying to develop a new type of wavelets and I found out a function that following a particular two scale relation. The function at a scale $t$ say $x(t)$ can be related in a finer scale $x(2t)$ ...
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66 views

How to design a variable slope highpass filter

I want to design some specific slope highpass filter to enhance speech; just like $1$ dB/octave, $2$ dB/octave and more. Is there a method to calculate the coefficients by specific slope?
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41 views

Pre-emphasis filter design

I am using the standard MATLAB filter function to design pre-emphasis filter. However, I am getting the wrong results back! I have the ground truth so I can check ...
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70 views

Continuous phase for phase delay calculus in FIR filters

I would like to estimate the phase delay accurately for any random FIR filter. The definition of the phase delay is the continuous phase divided by the angular frequency (with a sign change). That ...
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49 views

Very-short Hilbert transform FIR (or “recursive”) approximations

Hilbert transform is a quite sensitive topic here, since Gabor's paper, Theory of Communication, J. Inst. Electr. Engineering, London, 1946. Perhaps even more important than the Fourier transform. ...
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41 views

Combining IIM and MZT transformation

Split from thread: Correcting Impulse Invariance Method Back to this subject. Matt L suggested combining IIM and MZT b-coeffs to get the filter response improved at hihger frequency area. Couldn't ...
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17 views

Generating 3-dimension $1/f^\alpha$ noise

I'm stumped trying to find a way to generate a 3-dimensional $1/f^\alpha$ noise time series. Basically I want simulate a forcing that is $1/f^\alpha$ in the 2 space dimensions and $1/f^\beta$ in time, ...
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22 views

Adjusting corner frequency to constrain maximum disturbance in a high-pass filter

I have a first-order high-pass filter with transfer function: $$G(f)=\dfrac{G_0 jf}{jf + f_c}$$ where $G_0$ is the gain at high frequencies. If I input a sine wave with frequency 1 KHz and I want a ...
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94 views

Biquad Filter Optimization

I would like to try optimize a bit more the biquad filters indended for RIAA/non-RIAA equalization at low samplerates (44.1/48kHz). Best fit I get now is little below ±0.3dB for 44.1kHz and below ...
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47 views

What filter to use in audio analysis filterbank instead of FFT?

Standard bandpass filters can make super precise analysis filterbanks with 1024 to 4096 filters, on reaktor4. I tried in code to used cookbook BandPass and the result was aweful. Does someone know a ...
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39 views

How many non-zeros samples in convolution

If I have $b[n]$ of length 30 (30 non-zero samples) and $c[n]$ of length 40 (40 non-zero samples). How many non-zero samples will $a[n]=b[n] * c[n]$ have? (Note '$*$' is a convolution). I think ...
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396 views

Can two different impulse responses give the same frequency response?

I have two different impulse response each with different length, is it possible that they have the same frequency response?
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33 views

Real digital filter property

I am a beginner to study about the filter notion and property Being a real digital filter, (here "real filter" I means that its impulse response is real-valued) this formula is established. But I ...
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59 views

s_to_z (Pupalaikis)

Paper: Bilinear Transformation Made Easy - http://documents.mx/documents/easybilinearpdf.html Example of implementation - http://codepad.org/u3tvKn0S I get the same output for Butterworth lp example ...
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129 views

Correcting Impulse Invariance Method

I'm trying to find out if the correction (Jackson, Nelatury, Mecklenbräuker) could improve the (IIM based) filter response near Nyqvist. Here's my c++ routine (which is used for to calculate various ...
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50 views

DAC to Analog Filter to ADC

As the order of filter needed for digital information gets higher, it takes longer to process and requires more memory. Maybe analog filtering could be of use here. I know that the words analog and ...
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89 views

How to design an interpolated notch filter in Python to filter powerline harmonics

I have a a time domain data set that records the magnetic field vs time, which must be processed to reveal an embedded signal. This data also contains power line harmonics (i.e. multiples of 60 Hz) ...
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36 views

Quantifying how good I'm producing a spectral density

I recently asked a question here on how to create noise with a specific spectral density $S_{xx}(f)$. The helpful people of this stack exchange told me one way to do it was filtering white noise with ...
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29 views

questions on the wavelet digital filters

I am new in wavelet transform and digital filters. My knowledge on wavelet transforms was mainly from its applications with the implementation using Matlab or mathematica. So my question might be too ...
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19 views

Filtering squared-signal in MATLAB

This question seems to be trivial, but overwhelming to me. I am going to add white Gaussian noise to a sine-wave, hard-limit it, filter the output squared wave and check if the white noise effect is ...
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110 views

Fitting an IIR filter to a complex transfer function

anybody knows of better ways to fit an IIR filter to a complex transfer function than Matlab's invfreqz.m? I'm implementing a little transfer function fitting ...
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how to design wavelets from splines

Can any one tell me how to design wavelets from splines using matlab. whether we can make wavelets from higher order splines or only with B splines
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43 views

Phaser effect with feedback control IIR filter calculation

This question is possibly relevant to this one, but it's not duplicate as far as I'm aware. I'm trying to make phaser with feedback control as shown in the picture below: (Got it from here) First ...
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64 views

A C/C++ library for FIR filter design with “Don't Care region”

I need to get coefficients for my FIR filter. I know my pass band lets say between 350 - 400 Hz And my stop band(s) lets say 200 - 250 and 500 - 500 Hz, The other regions in the spectrum I simply ...
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49 views

Can you apply an audio filter/effect to only part of an audio signal and not get audio glitches?

I'm entertaining the idea of making a music-creating application. I'm a total newb at signal processing. The question that concerns me most right now is, if I apply a filter/effect such as ...
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63 views

How to select the length of a smoothing moving average filter?

I have a time series signal I need to smoothen to get rid of some noise. I decided to apply a moving average filter to this signal. I know the choice of the length of the MA is critical. How should ...
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72 views

Is there a difference between filtering a signal before or after differentiating it?

I have a time series and I want to apply: a differentiation a Butterworth filter Does the order theoretically (mathematically) make any difference? Does it make any difference in real life when I ...
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31 views

Differentials - Differences: Non causality in the system

I'm still learning DSP and referring to Oppenheim video lectures. In that lectures, differential difference equation is obtained for IIR filter design, in Lecture 14. $$\mathcal{L}[\frac{\mathrm ...
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34 views

Which method to choose to get linear phase response zero group delay low-pass filter?

Background: I do time-dependent simulations of physical systems. Like this: http://journals.aps.org/prb/abstract/10.1103/PhysRevB.91.115431 During the simulation, observables are recorded and later ...
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87 views

Multiple parallel IIR bandpass filters with different centre frequencies combined into one filter for optimisation… possible?

Before I begin, I have read these already: IIR filter parallelization Concept of combining multiple FIR Filters into 1 FIR filter I am processing audio using Csound in a high performance real time ...
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39 views

Transform matrix creation in compressed sensing

In Compressed sensing ECG reconstruction I would like to use biorthogonal wavelet basis as transform/sparsifying domain. I found out that wfilters command in MATLAB ...
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24 views

Specifications (N) FIR Low Pass Resamplig, Hamming Window

I'm learning about DSP and I've doubts. The resampling process can be do it with only one filter. $L$: Increment Sample Rate Integer $M$: Decrement Sample Rate Integer $f_S$: Frequency Sampling ...
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117 views

Problem designing a specific filter

I have the next problem. $H_{c1}(j\omega )$ is the ideal antialising filter and $H_{c2}(j\omega )$ is a real one. I'm asked to design $H(e^{j\Omega })$ so that $y[n]$ in the second diagram (the one ...
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41 views

Short lowpass filter that also extrapolates lines

I'm looking for a short lowpass filter that also extrapolates lines, [0 1 2 3] --> 4, so I need (correct me) $H([\ 0\ \ 0.25\ \ 0.5\ ]) \approx [ 1\ \ 2\ \ 0 ]$ . How close can one get to this with 2 ...
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MATLAB fvtool: Setting the passband ripple below 0dB for a FIR Filter

I'm new to using filter tools in MATLAB and I'm having a bit of difficulty. I'm designing a lowpass FIR filter and I'm trying to keep the passband ripple below 0dB in the magnitude response. So far, ...
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36 views

How to add single wavelength discrimination to the Kutulakos & O'Toole paper on a generalized Light Transport Matrix system

I wish to add single wavelength discrimination to the excellent paper Transport-Aware Imaging, Proceedings of SPIE Vol 9376, 937606 @ 2015 SPIE ,authored by Professor Kiriakos Kutulakos and Ph.D ...
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132 views

3dB and 6dB Per Octave Rolloff Digital Filters / Generating Pink and Brown Noise

So I would like to have a design method for filters with 3dB and 6dB per octave roll off -- for generating pink and brown noise respectively. I know the following 'pinking' filters exist: Filter to ...
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43 views

Interpolated impulse response for fraction delay?

I need to find a way to create some fractional delay in a signal processing application that I am working on. Separately to this, I have been messing around with basic filter design (despite reading ...